Abstract: An improved photoetch technique is presented of the multilayer resist type wherein a thin top layer of resist and a thick planarizing layer are deposited on a substrate and the thin layer is exposed and developed to produce a patterned resist layer. The improvement involves dissolving a suitable dye in a layer between the thin top layer and the substrate. The dye is preferably selected to absorb light of the wavelengths used to expose the top layer but does not interfere with processing of the other layers.

Abstract: An improved photoetch technique is presented of the portable-conformable-mask type wherein a thin top layer of resist and a thick planarizing layer are deposited on a substrate and the thin layer is exposed and developed to produce a portable-conformable-mask. The improvement involves dissolving a suitable dye in a layer between the thin top layer and the substrate. The dye is preferably selected to absorb light of the wavelengths used to expose the top layer but does not interfere with processing of the other layers.

Abstract: A method is disclosed for measuring the absolute value of the reflection coefficient between a transmission line of known characteristic impedance and the output port of an automatic level controlled source (i.e., ALC source). The ALC source is activated and a signal source is coupled to the output port of the ALC source via the transmission line to apply a test signal of amplitude V.sub.t to perturb the output signal of the ALC source. The magnitude of the amplitude modulation component of the resulting perturbed output signal is detected for use in combination with the value of V.sub.t in calculating the absolute value of the reflection coefficient. An apparatus is also disclosed for applying measuring the absolute value of the reflection coefficient. Alternatively, an on-carrier test signal is employed to perturb the output signal.

Abstract: An instrument is disclosed which performs measurements and calculates the average and the variance of the measurements. The particular instrument illustrating the invention is a spectrophotometer which measures sets of dark, reference and sample spectra for use in calculating an average absorbance spectrum and its variance. The measurements are performed in an order which enables the cancellation of measurement variation due to variation in instrument response. The order of measurements is determined by measurement subroutines which can be aggregated to produce a series of measurements performed over a user selected period of integration time.

Abstract: A multislope A/D converter is presented which employs a multislope integration technique enabling the use of a single comparator to detect polarity changes in the integrator output voltage. The A/D converter integrates a test signal during a run-up interval and integrates a discharging signal during the run-up interval as well as during a pre-run-down interval and a run-down interval subsequent to the run-up interval. The magnitude and polarity of the discharging signal are regulated in accordance with a switching scheme that converts circuit element mismatch error into offset measurement errors which can be eliminated by subtraction. The discharging current during the pre-run-down interval ensures that the slope of the integrator output voltage at the final polarity change is independent of test signal polarity thereby avoiding a comparator hysteresis error. A decade-run-down technique is employed during the run-down interval enabling the digital conversion to be implemented on a decade counter.

Abstract: A logarithmic attenuating circuit is disclosed for multiplying by a constant factor the logarithmic range of input voltages which can be accomodated by a variety of test equipment. The circuit functions as an amplifier having a gain which varies inversely with the root mean square of the output voltage. The effect of the circuit is to produce from the a.c. component of an input signal, an output signal having the same shape as the input signal but an amplitude of its a.c. component proportional to the n-th of the amplitude of the a.c. components of the input signal.

Abstract: An optical fiber is coated with an inorganic non-metallic coating to form a thin seal. The coating is preferably applied on-line by a process such as chemical vapor deposition.

Abstract: A method and device are disclosed for reducing the circuit size of a class of circuits including many memory cells and logic circuits. Selected drain to bulk or source to bulk transistor junctions are made leaky. The leaky junctions perform their intended (non-leaky) functions as well as the functions of certain other circuit elements. These other elements may therefore be eliminated from the circuit.

Abstract: An apparatus is disclosed for determining the vector voltage ratio of two a.c. input signals. A synchronous rectifying circuit, a phase shifter and a voltmeter are employed to detect the in-phase and orthogonal components of the input signals relative to a reference signal. A calculation section determines the vector voltage ratio from the values of these components.

Abstract: Basic steel rule dies are provided which can be combined to produce a variety of die cut patterns. Each basic die contains sufficient magnetic material to hold it in place on a steel chase during the cutting operation.

Abstract: A beam directing device is provided which employs one or more mirrors mounted on a single rotatable shaft. The orientation of the shaft controls the rotational orientation of these directing mirror(s) to direct the beam toward any of a number of sample or reference cells. Behind each cell is a cube corner which reflects the beam back to the directing mirror(s) for reflection toward the detector. In one embodiment, a shaft encoded senses the orientation of the shaft, the encoder output being servoed against a position signal to coarsely rotate the shaft in order to direct the beam to a sample cell and thence to a spectrograph slit. A pair of slit diodes detect the beam overlap on each side of the slit and their output is used to accurately position the beam on the slit to within one second of arc and correct for deviations in beam direction.